/*
 * -------------------------------------------------------------------------------
 * This applet connects to the server from which it was downloaded,
 * and then measures and reports the time it takes to download
 * a test page
 *
 * Author: Wolfgang Bluhm, mail@wbluhm.com
 *
 * Copyright 2001 The Regents of the University of California, All Rights Reserved
 * -------------------------------------------------------------------------------
 *
 * Some portions of this program were adopted from the book
 * "Java Examples in a Nutshell", 2nd Edition,
 * which carried the following copyright notice:
 * 
 * Copyright (c) 2000 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 2nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book (recommended),
 * visit http://www.davidflanagan.com/javaexamples2.
 */

import java.io.*;
import java.net.*;
import java.applet.*;
import java.awt.*;

public class DownloadTime2 extends Applet {

    long time_download;                  
    long time_start;
    boolean timedOut = false;
    String display_time;
    String address;
    URL url;
    String protocol;
    String host;
    String filename;
    String test_file = "misc/WolfgangBluhm.pdf";
    Socket socket;
    InputStream from_server;
    PrintWriter to_server;
    int port;
    final long MAX_TIME = 5000;
    final long BAD_TIME = 1000;
    int width = 75;
    int height = 15;

    public void init() {
        setBackground( Color.white );
    }

    public void paint( Graphics g ) {

        super.paint( g );

        try {

            display_time = "...";
//            System.out.print("Waiting...\n");
            
            g.clearRect(1,1,width,height);
            g.setColor( Color.black );
            g.drawString( display_time, 10, 15 );

        }

        catch ( Exception e ) { System.out.print("Some kind of error, first try block \n"); }

        try { 

            // time in milliseconds at start of download
            time_start = System.currentTimeMillis();

            // Now use the URL class to parse the user-specified URL into
            // its various parts.
            url = getCodeBase();
//            System.out.print(url.getHost() + "\n");
            protocol = url.getProtocol();
            if (!protocol.equals("http")) // Check that we support the protocol
               throw new IllegalArgumentException("Must use 'http:' protocol");
            host = url.getHost();
            port = url.getPort();
            if (port == -1) port = 80; // if no port, use the default HTTP port
            filename = url.getFile();
            filename += test_file;
//            System.out.print(filename + "\n");

            // Open a network socket connection to the specified host and port
            socket = new Socket(host, port);

            // Get input and output streams for the socket
            from_server = socket.getInputStream();
            to_server = new PrintWriter(socket.getOutputStream());


            // Send the HTTP GET command to the Web server, specifying the file
            // This uses an old and very simple version of the HTTP protocol

            to_server.print("GET " + filename + "\n\n");
            to_server.flush();  // Send it right now!
            
            // Now read the server's response
            byte[] buffer = new byte[4096];
            int bytes_read;

            // loop until download complete or timed out
            while((bytes_read = from_server.read(buffer)) != -1 && timedOut == false ) {     

//                System.out.write(buffer, 0, bytes_read);   // only for testing, do NOT use with binary files!

                if ( System.currentTimeMillis() - time_start > MAX_TIME ) {
                    timedOut = true;
                    display_time = "timed out";
//                    System.out.print( "timed out\n" );
                    g.clearRect(1,1,width,height);
                    g.setColor( new Color(255,0,0) );
                    g.drawString( display_time, 10, 15 );
                }
            }   
            
        }
        
        catch ( Exception e ) { System.out.print("Some kind of error, second try block\n"); }

        try {

            // time it took to download page
            time_download = System.currentTimeMillis() - time_start;
            if ( time_download <= MAX_TIME ) {
                display_time = Long.toString( time_download ) + " ms";
//                System.out.print( display_time + "\n" );
                g.clearRect(1,1,width,height);
                if ( time_download > BAD_TIME ) {
                    g.setColor( new Color(255,0,0) );
                }
                else {
                    g.setColor( new Color(0,255,0) );
                }
                g.drawString( display_time, 10, 15 );
            }
        }
        
        catch ( Exception e ) { System.out.print("Some kind of error, third try block\n"); }

        finally {
            stop();
        }

    } 

    public void stop() {
//          System.out.print( "Applet stopped\n" );
          try {
              if ( socket != null ) {
                  socket.close();
                  socket = null;
              }
          }
          catch ( Exception e ) { System.out.print( "Error closing socket\n" ); }
    }

    public void update( Graphics g ) {
        paint(g);
    }

}